We develop a theory of graph C*-algebras using path groupoids and inverse semigroups. Row finiteness is not assumed so that the theory applies to graphs for which there are vertices emitting a ...

A logarithm is the power which a certain number is raised to get another number. Before calculators and various types of complex computers were invented it was difficult for scientists and ...

Forbes contributors publish independent expert analyses and insights. I help people communicate data clearly with graphs. There are two main reasons to use logarithmic scales in charts and graphs. The ...

The inverse degree of a graph G with no isolated vertices is defined as the sum of reciprocal of vertex degrees of the graph G. In this paper, we obtain several lower and upper bounds on inverse ...

Control and inverse problems in wave equations and graphs constitute a dynamic field at the intersection of applied mathematics, engineering and physics. This area investigates how waves propagating ...

Forbes contributors publish independent expert analyses and insights. I help people communicate data clearly with graphs. In “When Should I Use Logarithmic Scales in My Charts and Graphs”, I showed ...